PPC740 G3 CPU on a machine that came with a 603e

[mg.man]

I'm not sure if the OP hangs out here, but just spotted this over on one of the FB Apple groups...







In the comments, he also got Tiger running! @max1zzz - this sounds like something up your street?

 

[Phipli]

I'm not sure if the OP hangs out here, but just spotted this over on one of the FB Apple groups...

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In tthe comments, he also got Tiger running! @max1zzz - this sounds like something up your street?

740s are a pain to find at good prices, or I'd have one in my 6500.

Note you don't get a backside cache, so performance won't be Beige G3 level

Still worth it.

 

[mg.man]

I'd have one in my 6500.

I was thinking G3-powered Takky CC!

 

[Phipli]

I was thinking G3-powered Takky CC!

So not all 603s are swappable. I think it is just the 603es? Does the Takky have a PGA or a QFP processor?

 

[max1zzz]

In the comments, he also got Tiger running! @max1zzz - this sounds like something up your street?

Maybe, but those 740's are damn expensive! Cheapest I found in a quick sarch was about £50 before shipping

 

[Phipli]

But I think I've heard of a G3 CC with an L2 Sonnet????

I've never dug myself into the CC bottomless pit of upgrades!

 

[mg.man]

Cheapest ... was about £50 before shipping

Hmm... still, cheaper than the L2 G3 cards tend to go for -- if you have the tools / skills to do the swap (which I don't!)

 

[Phipli]

Hmm... still, cheaper than the L2 G3 cards tend to go for -- if you have the tools / skills to do the swap (which I don't!)

It will be like 30% slower or something than a G3 upgrade without a backside cache. Almost as bad as a pismo with a broken cache. Can you prod the person for a benchmark?

 

[Daniël]

@dosdude1 is active on 68kMLA, so I'm sure he'd post it here as soon as he has the time.

I've been chatting with him and another buddy of mine about this, as I'm looking to do the same (already have the ICs necessary).
One obstacle was setting the VCore, my observation of it being set by a specific LDO voltage regulator ended up being correct.

On that subject, I also want to do a 604ev swap 6500, as I have two boards for experimentation, but the LDO regulator is going to be an issue.
The amount of power a 604ev needs, far exceeds the 3A that regulator can provide.

That, and I need a bigger heatsink, as that 604ev is a hot running die

 

[dosdude1]

Yep, it’s of course not going to be as fast as it would if it had backside cache, but is still somewhat of an improvement over the 603ev. Another idea I had was to make a custom interposer PCB, to adapt the 603ev BGA footprint into one of the ZIF sockets found on G3 PowerMacs, allowing you to simply install one of those G3 ZIF CPU modules (which of course have backside cache on them). But that’ll be sometime later. I did run a benchmark using MacBench, here are the results.

 

[max1zzz]

Another idea I had was to make a custom interposer PCB, to adapt the 603ev BGA footprint into one of the ZIF sockets found on G3 PowerMacs, allowing you to simply install one of those G3 ZIF CPU modules

That's a very interesting idea, though I would worry about the mechanical stability of placing a ZIF module on the BGA footprint. (Though I guess you could use the old heatsink mounting points to anchor the adapter in place)

 

[Phipli]

Yep, it’s of course not going to be as fast as it would if it had backside cache, but is still somewhat of an improvement over the 603ev. Another idea I had was to make a custom interposer PCB, to adapt the 603ev BGA footprint into one of the ZIF sockets found on G3 PowerMacs, allowing you to simply install one of those G3 ZIF CPU modules (which of course have backside cache on them). But that’ll be sometime later. I did run a benchmark using MacBench, here are the results.

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Thank you for the test results. If it is running at 266MHz that gives an idea. Much appreciated. I need to pull out my 300MHz 603ev results to work out what the increase over a 603 is.

 

[dosdude1]

Thank you for the test results. If it is running at 266MHz that gives an idea. Much appreciated. I need to pull out my 300MHz 603ev results to work out what the increase over a 603 is.

This is running at 300 MHz, as shown. It originally had a 275 MHz 603ev, I set the PLL config to 300 MHz to match the rating of the PPC740 I installed.

 

[Phipli]

This is running at 300 MHz, as shown. It originally had a 275 MHz 603ev, I set the PLL config to 300 MHz to match the rating of the PPC740 I installed.

Ah sorry, I was zoomed in on the scores.

 

[cheesestraws]

But I think I've heard of a G3 CC with an L2 Sonnet????

I have a Takky with a L2 sonnet G3.

 

[mg.man]

I have a Takky with a L2 sonnet G3.

Show off!

 

[mg.man]

This is running at 300 MHz

So 'no cache' = 45% of "with cache" performance? Ouch. Have you tried it with a cache SIMM in the L2 slot?

 

[mg.man]

Does the Takky have a PGA or a QFP processor?

Sorry, forgot to reply - it depends on which PM board you choose. The later ones require a mod to supply 3.3V. I'll see if I can find the Takky page and post it.

 

[mg.man]

Takky | powercc.org

A Takky Upgrade is to fit a logicboard of a PowerPC into the Apple Color Classic. It gives you much more Power than the original components.

powercc.org

 

[dosdude1]

So 'no cache' = 45% of "with cache" performance? Ouch. Have you tried it with a cache SIMM in the L2 slot?

This is with 512K of cache installed, but the cache slot is not the same as having backside L2 cache. So I suspect it'd be even worse with the cache module removed.